CSIR Study Identifies 19 Coronavirus Variants Capable of Evading Immune Response; One Responsible for Reinfection

Representative Image (IANS)

Of late, particular variants of the COVID-19-causing novel coronavirus in some parts of the world have been raising concerns with increased transmissibility. While it is normal for a virus to mutate to adapt to a particular region and conditions, mapping these mutated variants is a great challenge for virologists. But such mapping is of immense value in bringing a pandemic of such scale under control.

Now, a new breakthrough study by Indian scientists has identified at least 19 variants of SARS-CoV-2 virus in India with the ability to evade antibodies.

Moreover, out of these only one variant was found to possess the capability of causing re-infection. The researchers studied as many as 120 unique mutated variants of SARS-CoV-2, out of which 86 were found to possess the ability to dodge the human body’s immune response across 63 countries.

Escape variant of the virus

To understand the genetic epidemiology (distribution) of these tweaked variants, the team examined the dataset of 2,65,079 SARS-CoV-2 genomes from across the globe. The data was obtained from GISAID, a global scientific initiative that provides an open-access to genomic data of several viruses including coronavirus. The team sequenced 1,154 genomes in the labs of the associated institutes in India alone.

The study said, 19 mutations out of the 86 variants associated with immune escapes were found in India.

The detailed investigation of 26,917 genomes pointed out that 86 out of the 120 genetic variants associated with immune escapes from 63 countries. “Our analysis suggests that a number of genetic variants associated with immune escape have emerged in global populations,” reads the research paper, which is yet to be published.

While examining the global dataset, the team also came across a number of escape variants in different countries. The study reported that a mutant named N501Y from the UK, which has been found to be highly transmittable was detected from 290 sequenced genomes. It was specifically found from genome data of Australia, South Africa, the USA, Denmark and Brazil. In Australia, a mutant named S477N was found in 67% of more than 14,000 genomes samples that were studied.

One mutant variant causes re-infection

Advertisement One of the major findings of the study was the identification of a mutation named S:N440K. This particular genetically tweaked variant of coronavirus is responsible for one re-infection case that emerged from Noida in Uttar Pradesh.

This variant has a frequency of 2.1% in India and, as per the study, a high prevalence of this virus has been detected from Andhra Pradesh—with a number suggesting 33.8% frequency among the 272 examined genomes in the southern state.

The authors highlight that the time-scale analysis of S:N440K suggest that the variant has emerged only in recent months—around July-August in India. Apart from Andhra Pradesh, its presence has been detected from Maharashtra, Karnataka, West Bengal, Telangana, Uttarakhand, Haryana, Gujarat and Delhi.

The study concluded that more data and analysis are required to investigate the potential impact of these 19 variants on the vaccine efficacy in India.

The study was conducted by a team of researchers from various institutes under the Council of Scientific and Industrial Research (CSIR), these include Institute of Genomics and Integrative Biology (IGIB), New Delhi, Academy of Scientific and Innovative Research (AcSIR), CSIR-HRDC in Uttar Pradesh, and Kurnool Medical College in Andhra Pradesh.

As per reports, on December 26, the National Task Force (NTF) on COVID-19 has suggested conducting whole genome sequencing (WGS) of 5% of all positive cases nationwide. This has been suggested as all the RNA viruses including SARS-CoV-2 have the tendency to mutate and it will help to understand the spread. Under this, the Genomic Surveillance Consortium will be established to map the number of strains in circulation across the country.

The study has been uploaded to a preprint server and is yet to be published in a peer-reviewed journal. It can be accessed here.